Hmm The current main tug pilot at the London Gliding club in Dunstable ( pretty big ) has very little glider experience.
Saying that , aside from him, there are about 20 other members that have the qualifications to fly tugs, so they proably aren't looking, but you never know.
You need some knowledge of gliding so you don't tow the glider into a crap area with loads of sink, plus up need to maintant a fairly fixed rate of climb and speed.
Hope this helps
rob